In an internal combustion engine, a piston reciprocates within a cylinder. An air/fuel mixture above the piston is ignited, driving it down. The sequential firing of the pistons produces the power used to propel a vehicle. Both the piston and cylinder are typically made from a metal such as steel. The friction between the piston and cylinder is diminished by a lubricant such as oil. The oil circulates between a reservoir, the oil pan, and the engine.
In addition to lubricating the engine parts, the oil also conveys heat and debris from the engine. This debris can include fine metal shavings from the reciprocating engine parts. The oil circulates this debris into the oil pan and then back into the engine. An oil filter is typically used in the circulation path to filter larger particulate matter from the oil. However, the filter fails to remove all the metal filings from the circulating oil. The remaining metal shavings continue to cause excessive wear on the engine parts. Therefore, a need exists for a method of filtering the metal filings which supplements the oil filter.
One solution is to place a magnet into the oil pan to attract the filings from the oil and permanently capture them at the bottom of the oil pan. For example, U.S. Pat. No. 4,773,995 to Kondo, entitled "Magnet Filter," discloses a planar permanent magnet for use in a gear box, an oil reservoir, or the like. The magnet is partially wrapped by a magnetically permeable plate made of a magnetic metal. Opposite ends of the plate extend across the upper and lower edge portions of the permanent magnet piece. A sheet spring piece with flexed pieces at the opposite end portions is bent transversely of the sheet into an S-shape. When the magnet filter is fitted in a recessed portion of a gear case or the like, the free ends of the flexed portions at the opposite side ends of the sheet spring piece will bite into the inner peripheral wall of the recessed portion and prevent the filter from slipping out of the recessed portion.
If the device described in Kondo ('995) fails, the device can dislodge and damage adjacent parts. Additionally, since the device is placed in the oil pan, it is difficult to remove, clean and replace. Therefore, a need exists for a device that attaches easily to a car's oil pan and yet effectively filters any metal filings or particles from the oil. The device should exert enough magnetic force to draw the particles through even the thickest oil. Moreover, the device should allow the captured particles to be easily withdrawn through the oil plug hole during normal servicing. The device should also be usable with any wet sump oil pump that uses an oil reservoir. Therefore, the device should be usable by automobiles, farm equipment, trucks, compressors, and the like.